Joel is near the back with Dane when he realizes someone has come in the store, but he has his baby strapped to his chest and a stack of books balanced in each hand and he realizes there's not a chance he's going to be able to get up there before they lose interest and leave without dropping at least some of the books. And given that he's only just got Dane off to sleep for his afternoon nap, he doesn't want to do anything to wake him, which means he's going to have to rely on Spencer to have heard the door open so he can get there first. Especially if Spencer wants the books shelved properly, which Joel tends to have difficulty with at the best of times.

He manages it, though, sliding several books into place at once and then taking the others with his now free hand and making sure they end up on the correct shelf. By now he's sure Spencer has to have greeted whoever has come into the store, but he heads to the front anyway, his hand resting gently against Dane's back as he goes.